[X-Unix] dyndns to track your hardware (re: re: CL emailing)

[Stroller]

On Feb 7, 2004, at 5:05 pm, Peter Marreck wrote:
>
> ...I have an intranet IP and it won't help me if some tool on my 
> laptop which updates dyndns causes petespowerbook.dyndns.org to point 
> to 192.168.whatever... (Unless the tools that auto-update your dyndns 
> information somehow use the internet-facing IP from the router? Last 
> time I checked, they don't.)

Well, I haven't been paying attention too closely here, but it seems to 
me that it doesn't matter whether the laptop actually knows it's own IP 
when it sends you the email, because that information will be contained 
in the email headers (logged by the outgoing SMTP mailserver) when you 
receive it.

A couple of additional points: many SMTP servers block relay service 
for senders which are not logged on to one of their own IPs, to prevent 
spammers abusing their service, so you cannot hardwire your application 
with  the name of an SMTP server. Fortunately, Postfix, which comes 
with a default install of Panther, seems to connect directly to the 
SMTP server at the recipient's domain. Try `cat somefile.txt | sendmail 
you at some.address.com` and examine the headers.

You also need this application to run at startup, even if the laptop is 
not logged in as a user. You need to look in the /etc/rc scripts, I 
think, to do this. Of course, having it automatically log in as user 
Bob as startup will encourage any thieves to use it - if they are 
unable to log in the may not plug it into the network until they have 
reinstalled the o/s.

Hope you find this relevant,

Stroller.